Machine for dressing- millstones



-UNITED STATES lPATENT oEEioE.

E. YV. HAZARD, OF BINGHAMTON, AND CHAS. H. JENNER, OF ROCHESTER, NEV YORK.

MACHINE FOR DRESSING MILLSTONES.

Specification of Letters Patent No. 8,364, dated September 16, 1851.

To all whom t may concern Be it known that we, ERASTUS WV. HAZARD, of Binghamton, in the county of Broome and State of New York, and CHARLES H. JENNER, of Rochester, New York, have invented certain new and useful Improve ments in Machines for Facing, Furrowing, and Cracking or Checking the Surfaces of Millstones, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 is a side elevation; Fig. 2, a plan; Fig. 3, a vertical section taken at the line A, a, of Fig. Q, and Fig. t sections o1 the lever fo-r regulating the force of the blow of the cutter.

The same letters indicate like parts in allthe figures.

rlhe mechanism is mounted on an open bed which is to be placed on the face of the stone to be dressed. This bed is formed with ways on which slides the first carriage, which first carriage has ways on which a second carriage slides at right angles to the first, and to this second carriage is hinged one end of a frame which carries the chisel and the mechanism for operating it and giving the feed motion for determining the cuts.

Our invention consists in combining with the lever which operates the feed hand or hands and which receives motion from a rotating cam or tappet, a weighted lever or the equivalent thereof, which falls by its weight the moment the lever is carried back to give one feed motion, so that the end thereof shall act as a stop to arrest the feed motion that the cutter may continue to strike in the same place until the attendant lifts up the lever topermit the feed motion to continue.v

In the accompanying drawings a represents an open bed frame which is to be placed on the millstone to be dressed and the said frame is provided with three parallel ways I), l), b, on which slides what we denominate the first carriage c, the two side pieces of which constitute ways on which slides the second carriage (l so that the two carriages slide on their appropriate ways at right angles to each other. To one end of the second carriage 1s jointed the rear end of a frame e called the cutter frame, theA other end of which is provided with an adjusting screw f, (turned by a crank handle) the end of which rests at g on the second carriage, so that by the turning of the said screw, the cutter frame can be elevated or depressed at pleasure. The rear end of the hinged frame e carries a rock shaft it, from which projects an arm or helve c', the forward end of which is rounded to fit a corresponding socket in the cutter stock j. said stock is free to turn on the arm or helve to adjustthe edge of the cutter to the face of the stone, and then it is there secured by a temper screw 7c, which however bears on an interposed plate (Z) fitted to the arm or helve so as to prevent the temper screw from injuring the rounded surface. The cutter m is fitted to the stock, and secured by a screw jaw n in the usual way.

To the arm or helve, and near to the cutter stock is jointed a rod 0 the upper end of which slides in, and is guided by, a bar p, and the upper end of said rod is formed with a hook or lip g, which is acted upon at every revolution by a tappet r on the main shaft s to lift the cutter, which after the tappet has passed is forced down to make the cut by a spring t that bearsV on the helve,

The

the downward motion being arrested by a to a rock shaft w to one end of which is,

secured a hand lever by means of which the tension of the spring can be increased or reduced to graduate the force of the blow. The said hand lever extends so far in front as to be within reach of the operative, who can fix it in any position desired by hooking it into any of a series of teeth y, on one of the standards of the hinged frame.

The main shaft s that carries the tappet r has its bearings in the standards of the hinged frame. On one end of the said shaft there is a fly wheel a and on the other a pinion b which is driven by cogs on the inner periphery of a wheel c. The main shaft carries a cam d which acts on the upper end of a lever e that has its fulcrum at f, the lower arm thereof being` attached to a spring g, the tension of which tends constantly to force the upper arm toward the cam. The range of motion of the said lever toward the shaft is regulated by a set screw t, so that the amount of vibration which shall be imv parted to it by the cam can always be determined by the set screw. Two feed hands e", t, are jointed to the lower arm of the lever and adapted to engage two sets of ratchet teeth j, j', one finer than7 the other and both attached to the lower carriage,- and one set corresponding with each of the feed hands, so that if it be desired to feed or move the cutter fast, the handA corresponding with the coarse teeth is set in action and the other lifted out, and vice versa. In either case, however, the set screw must be setto regulate the vibrations of the lever. As it is frequently necessary to repeat the blows of the cutter in the same place, (that is, without shifting the position of the cutter) there is combined with the lever that rows of different millstones, the inclined operates the feed hands, a stop lever 1c that hangs on a fulcrum at Z so that the weighti The of the forward end shall predominate.

lever e is notchedor cutout atm, so that when the stop lever la is lifted up, the spring g may force it forward to draw back the feed hand, and thus put the parts in a positionto give the feed when the cam passes around; but the moment the lever e isf forced back by the cam, the stop lever, byE its weight, assumesthe position represented; -in the drawings to stop the further progress i Aof the feed motion until the loperator finds that the desired depth of cut has been made, and then he simply lifts thel stop lever to f of the said screw is let fnto a slot in a standard g. ofthe'iirst carnageand there held restart the feed motion.

As the first carriage with the second can riage on it slidesV on the bed". frame in one;vy direction, and the second carriage with the; hinged frame carrying vthe cutter and its appendages, slides` thereon at right angles it? will be apparent that the cutter can -be car-fl 'ried to any desired part of the faceof the, stone, and that when so set, a series of cuts;V can be made parallel toeach other and asf near together or as far apart as may bei desired. And as the stop or bridle deter-2 mines the downwardmotion of the cutter, and this together with the cutter, and the; mechanism which operates it is attached to; and makes part of the hinge frame whiehf can be elevated or depressed, it follows that? the machine can be set to make any desired; number of cuts, all of the same depth. And.l as the machine will continue to repeat the;` same cut until the stop levery is lifted to set in action the feed motion whatever may be the varying texture of the stone, the cuts will l all be made of` the required depth for the?. attendant will not start the feed motion until he finds that the arm or helve of they cuttercomes down to the bridle or stop.

. So far we have described the machine as applied to thepurposeof checking or crack ing the face of lands, that is, the surface ofA .the cutter should descend. v For this purpose as described.

the adjusting screw f, before mentioned is tappedin a block secured, to the hinge frame by` ascrew bolt n and when the machine is to be set for cutting the furrows and main furrows, theblock and screw are shifted to the position represented by red lines in Fig. 8, so that the end of the said screw shall rest yon aninclined plane of attached to, and making part of the first carriage, so that every feed inc-tion the cutter will be let down a little lower and thus make the series of cuts on an inclined plane. l

Asit frequently occurs that different degrees of inclination are required in the furplane 0 on which thepoint of thev screw f, rests, as represented in red lines is provided with a stud or shank projection t which sets inl a slot in the lirstcarriage c and against said 'stud or shank projection is placed'a SetV down by a securing pin r. The Said screw is provided with a crank handle s by means of which the operativecan bring the cutter to any line desired for starting, -and then feed for the facing and furrowing, as these operations' require a very gradual and tine feed, the feed handsbeing merely employed to fed the cutter for checking or cracking the surface of the lands.

Ve have thus fully described the manner of constructing the machine as we have essayed it with success, but we do notwish to confine ourselves tothis precise mode of construction, as it may be changed without `changing the principle or mode of operation which we' have invented.

We claiin- In combination with the feed lever (e) operated bythe cam (d) to work the feed bands the ,employment of a weighted stop lever, or the equivalent thereof acting in the lnotch (772/) of the lever (e),substantially as described, which said stop shall be self acting to stop the feed motion that the cuts may continue in the same place, until the .feed motiony is restarted, and thus insure the "cutting vof the stone 'to the' required depth, whatever may be vthe texture thereof,

ERASTUS W. HAZARD. CHARLES H. JENNER. Witnesses: v f WM. BISHOP, l

' Y Roer. B.I CAMPBELL. 

